1. Field of the Invention
The present invention relates to a retrofit insert for use in a standard laboratory muffle furnace which allows heating of small objects to a temperature up to approximately 1000.degree. C. in the presence of a reducing atmosphere.
2. Description of the Prior Art
Reduction furnaces presently commercially available are typically complex and relatively large in size and cost. Some models utilize the cracking of ammonia (NH.sub.3) into nitrogen and hydrogen gases to attain the reducing atmosphere, but these usually have minimum operating temperatures in excess of 600.degree. C. The cost and complexity of the aforementioned devices usually precludes their use in a laboratory where, for the amount of use projected, the cost would be unjustifiable.
The problem with prior art high temperature air furnaces, that were built for general laboratory use, is that they are not readily convertible for a reducing furnace application. These prior art laboratory air furnaces frequently contain muffles which are porous or have non-lock tight closures. This construction frequently results in the work processed being oxidized or permits the buildup of an explosive gas mixture in the muffle.